Revision as of 03:05, 6 October 2009

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The 2009 Victorian bushfires on Saturday 7 February 2009 were the worst bushfires in Australia's history, surpassing both the Ash Wednesday fires in 1983 and the Black Friday fires in 1939.

The bushfires travelled at alarming speed, up to 100km/h, across farmland and through plantations and heavily "managed" forests, including forests where recent fuel reduction burns had been done.

Bushfire and climate scientists have confirmed that Victoria's hottest day every, combined with very strong north winds, created conditions for an unstoppable firestorm.

Kilmore East and Murrindindi Mill initial fire tracks

Initial track of the fires that started at Kilmore East and Murrindindi Mill.

Note: this map is not accurate

Note that the fire fronts changed direction to travel North East after the southerly wind change. This wind change created a huge fire front along the entire edges of the previous fire track, and resulted in Flowerdale being burnt.

The bushfires slowed considerably when they eventually entered Melbourne's water catchments, but they continued to burn. Intact wet sclerophyll forests in our water catchments are less prone to burning, and temperatures and wind speeds have eased.

Kilmore and Murrindindi Mill fires merge to form the Kinglake fire complex.

Wilsons Promontory fire started by lightning

Weather

The fires came as Melbourne reached its hottest ever temperature of 46.4 degrees.[1]

The extremely hot temperatures were accompanied by very strong north westerly winds, which changed to strong south easterly winds in the late afternoon.

The combination of extreme heat and very strong winds resulted in the highest ever fire danger index warnings recorded in Australia.[2]

The fire danger index scale ranges from 0 to 100, with 100 being extreme fire danger. During Saturday 7 February, index warnings above 150 across Victoria were advised, with some areas exceeding 200.

Wind chart from Fawkner Beacon in Port Phillip bay illustrating wind change to Southerly at approximately 5pm in Melbourne

Links between extreme bushfires and climate change

Professor David Karoly has stated that the extreme weather parameters on and leading up to February 7 were the most important factor, including:

Record low rainfall - 35 days of no rain up to February 7

Record low relatively humidity on February 7th of 5%

The hottest recorded temperature of 46.7 on February 7

The strong north winds and the southerly wind change on February 7th were not unusual in themselves, but combined with the above factors, and ignition of the fires, the results were catastrophic.

Bushfire index ratings compared between extreme fires are:

100: Black Friday in 1939

120: Ash Wednesday in 1983

140 to 190: Black Saturday. These figures have never been seen before and are regarded as in the "catastrophic" range.

Professor Karoly also pointed out that CSIRO scientific predictions are that the current rate of climate change were are experiencing will result in 4 times as many extreme fire dangers days like Black Saturday each year by 2050.

He concluded with these observations:

A tragedy occurred with the bushfires in SE Australia on 7 February 2009

It is difficult to separate the influences of climate variability, climate change, and changes in fire management strategies on observed increases in fire activity

Observed increases in forest fire activity have been linked to climate change in the western US, in Canada, in Spain and in Greece.[3][4]

Impacts of fires

Loss of property=

The fires have destroyed at least 1,834 homes, with thousands more suffering damage.

The fires have left an estimated 7,500 people homeless.

Deaths

As at May 13 , 2009, 173 people are reported dead.

Several million native animals are estimated to have died.

Carbon emissions

Millions of tonnes of carbon have been released to the atmosphere. Australia's total emissions per year are around 330m tonnes of CO2. Previous research has shown that the bush fires in 2003 and 2006-07 had put up to 105m tonnes of carbon dioxide into the atmosphere because they burned up land carrying 50 to 80 tonnes of carbon per hectare. This time, however, the forests being destroyed are even more carbon-rich, with more than 100 tonnes of above-ground carbon per hectare. The affected area is more than twice the size of London and takes in more than 20 towns north of Melbourne, so the CO2 emissions from this year's disaster could be far larger than previous fires.[5]

Water harvest falls

Water collection in dams affected by Victoria's bushfires could fall by 30 per cent in the decades ahead, Melbourne Water officials have warned. Three of Melbourne's four most important reservoirs have had fires in their catchments during the past 10 days, with two of the catchments suffering significant damage.
[6]

Power and phone network failures

The following power lines which supply Melbourne with electricity failed during the bushfires:

Two power lines in the Latrobe valley, due to the Churchill fire

One power line to the north of Melbourne, due to the Kilmore fire

An electricity spokesperson stated on the Radio 774 on February 7 that Melbourne was very close to losing its power as a result of these fires. If another power line had been impacted the entire grid would have been temporarily shut down.

Phone networks failed in fire areas when the following infrastructure was destroyed by fire:

poles and wires for landline phone networks.

transmitter towers for mobile networks.

Measures to reduce impacts of bushfires

After the fires, there has been much speculation about measures that could be adopted to reduce bushfire risks and impacts. A Royal Commission with a wide terms of reference has been announced by the Victorian Government to investigate these bushfires and make recommendations.

Some possible measures that may reduce bushfire risks and impacts include:

Fire-proof bunkers under or near houses. However, bunkers are not classified as structural items under the building code, so improved regulations for them are required.

Larger community fire-proof buildings in towns and schools.

Fire-retardant plants near buildings.

Clearing vegetation for the close proximity of buildings.

An early warning notification system via landline and mobile phones

Possible new building regulations

New building regulations to improve the fire resistant qualities of building such as:

Minimise or eliminate external woodwork such as deckings

Gutters which do not trap burning embers and leaves

Sealed roofs which do not allow burning leaves and embers in

Use of earth berms to protect building walls

Double glazed windows to provide more robust windows

Fire proof shutters over windows

Sprinkler systems to wet building roof spaces and walls

Gutter and downpipe systems that can be blocked and filled with water

Fire resistant wall materials such as concrete or tin

Provision of battery or petrol/diesel powered pumps and fire proof hoses for extinguishing and fighting fire

Concrete water tanks (plastic tanks were melted by the bushfires)

Steels Creek house - built to survive a bushfire

Steels Creek house

Despite being attacked twice by fire on Black Saturday from two different directions Mr Williams' Steels Creek home stood solid while everything around it was destroyed. Four of his neighbours died.

The fire that bore down on his house was about 1200 degrees, hot enough to soften the metal but not melt it. Glass doors and windows in his house are all double-glazed. Some of the outside panes cracked in the heat. Next time he'll add shutters

Features of the Steels Creek house that assisted its survival:

Double-glazed doors and windows, some outside panes cracked in the heat

A sprinkler system operates on three levels. In total, there are 30 sprinkler heads around the house, using 200 litres a minute, can create a water canopy around the house[7]

Fuel reduction burning controversy

After the bushfires, some commentators have claimed that increased fuel loads and a lack of fuel reduction burning in forests contributed to the severity of the fires. However, the fires burnt through plantations, farmland and forest areas, including regions where extensive fuel reduction burning had been done. For example:

extensive fuel reduction burning has been conducted around Marysville over the last decade and a firebreak was constructed around the town.[8]

Two thirds of the Bunyip fire was on cleared farmland

The Kilmore fire started on and traversed large areas of farmland before it entered forested areas.

A relatively small grass fire in Narre Warren burnt several houses before it was contained.

Kevin stated that the extreme weather dominated the fire behaviour rather than fuel loads which played a lesser role. As an example, he mentioned the Lara bushfire on grass paddocks on 8 January 1969 along the Geelong Road that killed 17 people trapped in their cars. In total, 280 fires broke out on the 8th of January 1969. Of these, 12 grass fires reached major proportions and burnt 250,000 hectares. The fires also destroyed 230 houses, 21 other buildings and more than 12,000 stock.[3]

Communications technology

The scale and speed of the bushfires placed extremely high demands on emergency communications, including:

the emergency 000 telephone service overloaded with call, some of which were dropped

radio traffic to and from CFA vehicles was very congested. Many trucks were unable to provide regular situation reports.

single "hub" radio operators had to deal with many mobile units.

mobile and land line phone network infrastructure were both badly damaged by the fires, and in many places were inoperable

overloading of mobile phone networks due to high call volumes and congestion.

Distributed and asynchronous communications technologies could be more effective for handling the large volume of messages and information that needs to be shared in these type of emergencies. Options include:

Rebuilding with prefabricated "pods"

House re-Growth Pod

House re-Growth Pod

The House re-Growth Pod has been designed by architect who wanted to help with the re-building process of fire destroyed homes in Victoria. The dwelling is a completely self contained concrete service pod which is s a permanent and cost effective housing unit which can assist in the rebuilding of the fire devastated town-ships of Victoria.

The robust pre-fabricated concrete structure has been designed to be built upon, but in the short term acts as a habitable starting point for the building of a new home. The units can be prefabricated, delivered and connected to services rapidly allowing families to begin the process of re-building without displacement from their communities[9][10]

Royal Commission

The Royal Commission's terms of reference were released on Monday 16 February 2009 and include inquiring into and reporting on the following matters:

The causes and circumstances of the bushfires.

The preparation and planning by governments, emergency services, other entities, the community and households for bushfires in Victoria, including current laws, policies, practices, resources and strategies for the prevention, identification, evaluation, management and communication of bushfire threats and risks.

All aspects of the response to the 2009 bushfires including immediate management, response and recovery, resourcing and coordination and equipment and communication systems.

Measures taken to prevent the disruption to the supply of essential services such as power and water

Any other matters deemed appropriate.

Recommendations arising out the inquiry are indicated on:

The preparation and planning for future bushfire threats and risks, particularly the prevention of loss of life.

Land use planning and management, including urban and regional planning

Fireproofing of housing and other buildings, including materials used in construction

The emergency response to the fires

Public communication and community advice systems and strategies

Training, infrastructure, and overall resourcing needs.

Causes of death

Radiant heat; trapped in dwelling for shelter or while defending against fire